This is a simple question and sorry for it sounding stupid but when/how do you get your digi card?
I am waiting for my provisional and then i am off to book theory test 
dft.gov.uk/dvla/onlineservic … forms.aspx
Fill out that online order form and tick the pack you need "ST1A Pack " it costs about £38 when i had mine, needs to be renewed every 5 yrs at a cost of £19.
Form you need is here.
dft.gov.uk/dvla/forms/~/medi … D777B.ashx
Print that out and fill it in then send it to the DVLA.
cheers guys
reason why i asked is because i always thought they give it to you once you pass but it looks like another gain for the government